A third of the women who are not currently using contraception (and not pregnant, trying to get pregnant, sterilized, had a hysterectomy, or whose partner had been sterilized) say they are not currently using any method of birth control because they are not currently having sex (33%). An almost equal proportion of those not using contraception (34%) say that they are not using it because they are infertile or don’t need it.

Here are some other reasons:

Don't like birth control: 6.8%
Don't care if become pregnant: 4.4%
Side Effects: 5.4%
Just had baby: 2.5%

It sounds like a heck of a lot of women just don't want to use birth control.

The contraception pushers won't be happy until every woman has an IUD in her.